IT ISSUE · NETWORKS AND CONNECTIVITY
Firewall blocking a service
Worth asking whether it should be unblocked. A refusal is often the only part working correctly.Before this becomes a question about how to unblock it, it is worth asking whether it should be unblocked. A firewall refusing a connection is often the only part of the system doing exactly what it was asked to do.
What you may notice
- An application works from home but not in the office.
- A new cloud service won't connect.
- A vendor asks you to open a port or allow a range of addresses.
- Something that worked last month stopped after a change.
- One site is unreachable while everything else is fine.
Understand the rule before changing it
We identify what is being blocked, what it is trying to reach, and why the rule exists. Then we look at whether the vendor's requirement is specific or a blanket request, and whether a narrower change would do the same job.
Sometimes the answer is that we aren't making the change. A vendor asking for a wide range of addresses opened because it is easier at their end is asking you to carry a risk on their behalf. We'd rather explain that, and put the narrower option to them, than quietly widen your network and say nothing.